Nonwarping trussed door



11, 1951 G. s. GREEN ET AL 2,578,240

NONWARPING TRUSSED DOOR Filed May 11, 1949 INVENTOR.

GEORGE .s. 6/?/V B ZAWl-PE/VCE f. HOW/I77 Patented Dec. 11,1951

NONWARPING TRUSSED DOOR George Schuyler Green, Cape Elizabeth, Maine,and Lawrence F. Howatt, Belmont, Mass.

Application May 11, 1949, SerialNo. 92,694

Claims.

This invention relates to doors, and more particularly to a flush-typewooden door which is provided with adjustable means for counteractingwarping stresses in said door.

Heretofore, a disadvantage of flush type wooden doors has been theirtendency to warp under certain conditions. Even though the manufacturermight take great care touse well seasoned material, aninherent warpingtendency was likely to develop frequently, so that it was not alwayspossible to predict what the behavior of the doors would-be afterinstallation.

Furthermore, doors are frequently; installed at locations. in whichtheir opposite faces are subjected to unequal conditions of moisture ortemperature, thus causing the doors towarp despite the fact that theymay havebeen made of wellseasoned wood.

Accordingly, one object of this invention is to provide a door whichincludes one or more adjusting devices which are. adaptedv to maintainstresses in; the door which are equal and opposite to warping stressesthat may occurtherein.

Another object is to provide a door of the above nature in which theadjusting devices are adapted to bend the door laterallyof its plane,

whereby the door may be held flat or selectively bent so as to conformto a warped door jamb.

Another object is to provide a door of the above nature in which theadjusting devices are entirely concealed and are so arranged as to avoidinterference with the trimming and fitting of the door or with theinstallation of door hardware.

Another object is to. provide a door of the above nature in which theadjusting devices comprise tension members which are so arranged as toprovide a truss action Which-will restrain bending or warping of thedoor.

A further object is to provide a door of the above nature which. will besimple in construction, inexpensive to manufacture, easy to install andadjust, compact; ornamental in appearance, and very efiicient anddurable in use.

With these and other objects in view, there has beenillustrated on theaccompanying drawing. one form in which the invention may convenientlybe embodied in practice.

In the drawing,

Fig. 1 is a perspective view of the improved door as it would appearwith one face covering removed so as to show the interior construction.

Fig. 2 is a fragmentary view of a'corner portion of the door on anenlarged. scale, showing how the tension. members are. anchored.

Rig. 3. is a cross-sectional. view takenon the line 3-3 of Fig. 1.

Fig.4 is a perspective view of; the door; on a reduced scale, partlybroken. away. Showing the door hardware applied. thereto.

Referring now to the drawing, in which like reference numerals denotecorresponding parts throughout the several views, the improved flushtype door is provided with a rectangular frame I0 comprising a pair ofstiles II, I2, which are rabbeted at their inner corners so as toreceive the ends of a top rail I3 and a bottom rail I4.

The frame I0 is also provided with a pair of inner stiles I5, I6 whichare disposed in spaced parallel relation to the stiles II, I2, and aresecured at their ends in slots in the top rail I3 and the bottom rail I4.

In order to serve as bases for latch mechanism or other door hardwarewhich may be mortised or otherwise attached at central edge portions ofthe door, provision is made of elongated lock blocks II, I8, which arecentered between the rails I3, I4, and are secured between the stilesII, I2, and I5, I6, respectively. It Will'- be noted that the provisionof the lock blocks; I'I, I8 at both edges of the door will render thedoor reversible for purposes of installation, so that the latchmechanism may be applied to either edge of the door, while the verticalextent of said lock blocks will permit a substantial range in the heightat which the latchmechanism may be applied.

In order to counteract warping tendencies and otherwise control bendingof the door, the opposite vertical edge portions thereof are providedwith adjusting devices comprising tension members or wires I9, 20, and2I, 22, respectively, which are disposed between the outer stile II andthe inner stile I5, and between the outer stile I2 and the inner stileI6, respectively. The central portions of the wires I9, 20 arepreferably flattened and are disposed in shallow vertical grooves 23formed in opposite faces of the lock block II, respectively, While thecentral portions of the wires 2 I, 22 are similarly flattened and aredisposed in shallow vertical grooves 24 in opposite faces of the lockblock I8.

In order to permit the wires or tension members I 9, 20, 2|, 22 to exertlateral forces upon the respective lock blocks I1, I 8, said wires aredisposed in crossing relationship above andbelow the respective lockblocks, and are secured to end portions of the top and bottom rails I3,I4 in such a manner that the ends of each wire are anchored adjacent oneface of the door, while the central portion of the wire is bowed overits respective lock block and lies adjacent the opposite face of thedoor.

In order to anchor the ends of the wires I 9, 20, 2|, 22, the, ends ofthe top and bottom rails, I3, I4 arehorizontally slotted midway of theirthickness so as to receive four identical apertured metal, anchor plates25, one of which will be described with reference to Fig. 2. The ends toof the wires I9, 20. are provided withscrew threads 26 whichare engagedby headed female anchor screws 21 extending inwardly through theapertures of the anchor plate 25--.the sides of the rail I3 beingprovided with vertical side slots 28 to accommodate said screws 21, andalso to permit access to the screw heads and thus permit manualadjustment of the wires I9, 20, as by means of a screw driver.

It will be noted that the anchor screws 21 are disposed in respectivelyoffset relationship longitudinally of the rail I3, this arrangementbeing for the purpose of maintaining the crossing portions of the wiresI9, 20 separated so as to avoid any noise that might otherwise resultfrom vibration of the wires I 9, 20 if said wires should lie in contactwith each other.

Thus, it will be seen that the screws 21 may be turned in appropriatedirections so as to tighten the wire I9 and loosen the wire 29, or viceversa, this operation resulting in a lateral force upon the lock blockI! for bending the door. However, in order to prevent the wires I9, 20from twisting while the screws 2'! are being adjusted, provision is madeof horizontal guide plates 29, one of which is secured to the stile I Iand the inner stile I inwardly of the top rail I3 (Fig. 2), the facingsurfaces of said stiles preferably being slotted to receive and hold theends of said guide plate. The opposite edges of the guide plate 29 areprovided with offset rectangular slots 30 which slidably andnon-rotatably embrace flattened portions 3| of the wires I9, 20.

It will be understood that four of the guide plates 29 will be provided,one in each corner portion of the door for engaging flattened portionsof the respective wires and thus preventing the wire ends from rotatingduring adjustment thereof by means of the screws 21.

The door shown herein is of the flush type,

and is provided with a core structure in the form 0 of a plurality ofvertical upper and lower reinforcing members or strips 32, 33, which aresecured above and below an intermediate rail 34, said strips beingsecured in slots in said rail 34, in the top rail I3, and in the bottomrail I4.

As a further deterrent against warping, the door'may, if desired, beprovided with a pair of rigid vertical metal members or bars 35, 33,which are secured against the inner surfaces of the inner stiles I5, I6by any suitable means, such as screws, and which have inturned ends 31,38, 39, 40, secured to the inner surfaces of the top rail I3 and thebottom rail I4.

The frame III, the lock blocks I'!, I8, the inner stiles I5, I6, thereinforcing strips 32, 33, and the intermediate rail 34 are of equalthickness and are so secured that their opposite edges are dis posed inparallel planes, whereby flat coverings 4|, 42 of any suitable material,such as plywood, may be applied thereto. The component parts of the doormay be secured together by any suitable means, such as nails and glue.

Operation In installation, the door herein disclosed may be fitted inthe usual manner by trimming or planing the ends and edges of the door.

It will be noted that the anchor plates 25 and other metal parts in thedoor are located a substantial distance inwardly from the outer edges ofthe door, so that approximately one-third of the thickness of the stilesI I, I2 and of the rails I 3, I4 may be trimmed away if necessary duringthe operation of fitting the door. Y

Hinge butts 43, 44 may be applied to one edge of the door, while a latchmechanism 45 may be mortised into the opposite edge of said door.

All of the adjusting screws 21 preferably will have been so adjusted bythe manufacturer as to hold the door perfectly flat. However, if thedoor is found to require adjustment at the time of installation, one ormore of the screws 21 will be turned in the appropriate direction so asto bend the door as desired.

The tightening of any particular screw will, of course, reduce theconcavity of the face of the .door which is adjacent that particularscrew.

Thus, for example, if the door is found to be warped so that the doorcovering 42 is concave, the tension member or wire I9 will be tightenedby turning one or both of the screws 2! at its ends, thus drawing thelock block I! (as seen in Fig. 1) toward the observer and forcing thetop and bottom rails I3, I4 away from the observer. During thisoperation it may be found desirable to decrease the tension in the wire20 slightly by adjusting the one or both of the screws 2'! at the endsof said wire.

It will be understood that the wires I9, 20 may be adjusted so as tocontrol bending of the door adjacent the stile II, while the wires 2|,22 may be adjusted in a similar manner to control the warping of thedoor adjacent the stile I2. Inasmuch as the adjusting screws 21 arereadily accessible, the door may be readily adjusted so as to overcome awarping tendency at any time subsequent to installation.

While the wires or tension members I9, 20, 2|, 22 (and also the metalreinforcing members 35, 36) will tend to prevent warping of the door, itwill be understood that warping stresses cannot be entirely resisted bynon-adjustable reinforcing members because of the physical principlethat any stress is necessarily accompanied by a strain. In the presentinvention, when warping occurs, it will merely be necessary to adjustthe tension of one or more of the wires I9, 20, 2 I, 22 by means of theadjusting screws 21, thus furnishing the additional force necessary tobring the door back into a fiat condition.

In some instances, it may be desired to employ the wires I9, 20, 2I, 22to produce a controlled warping of the door, as for example when it isdesired to make the door fit against a warped door jamb. In this event,the screws 21 may be easily adjusted so as to make the door fit the jambin the desired manner.

As an alternative arrangement, the door may be so constructed that thetension members or wires I9, 20, 2|, 22 are disposed in non-crossing andapproximately parallel relationship, whereby adjustment of said wireswill produce a bending effect which is merely the result of tensionchanges adjacent opposite faces of the door.

While there has been disclosed in this specification one form in whichthe invention may be embodied, it is to be understood that this form isshown for the purpose of illustration only, and that the invention isnot to be limited to the specific disclosure, but may be modified andembodied in Various other forms without departing from its spirit. Inshort, the invention includes all the modifications and embodimentscoming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, andfor which it is desired to secure Letters Patent, is:

1. In a door, top and bottom rails, an outer stile, an inner stilespaced from said outer stile, a lock block secu ed between said stiles,a pair of substantially coextensive tension members, and means anchoringopposite ends of each member respectively to said top rail and to saidbottom rail between said stiles, said tension members embracing saidlock block and being held in oppositely bowed positions thereby, saidanchoring means comprising devices for independently varying the tensionin said tension members, whereby a warping tendency in the door may becounteracted.

2. The invention as defined in claim 1, wherein said top and bottomrails are engaged in rabbets in said outer stile, whereby the reactionof said tension members may be efliciently taken by said outer stile.

3. The invention as defined in claim 1, in which said anchoring meanscomprise an anchor plate mounted in a horizontal slot in one of saidrails and having a pair of apertures, said one rail having verticalslots providing access to said apertures, and a pair of headed screwsengaged in said apertures and having threaded engagement with adjacentends of said tension members, whereby the tension in said tensionmembers may be independently adjusted for bending the door.

4. The invention as defined in claim 1, in which said anchoring meanscomprise an anchor plate mounted in a horizontal slot in one face ofsaid rails and having a pair of apertures adjacent opposite faces of thedoor, said one rail having vertical slots providing access to saidapertures, and a pair of headed screws engaged in said apertures andhaving threaded engagement with adjacent ends of said tension members,said tension members crossing between said anchor plate and said lockblock, whereby the tension in said tension members may be independentlyadjusted for bending the door.

5. The invention as defined in claim 1, in which central portions ofsaid tension members are disposed in slots in opposite faces of saidlock block, said door further including door coverings secured toopposite faces of said stile, said rail, and said lock block.

GEORGE SCHUYLER GREEN. LAWRENCE F. HOWATT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 138,611 Callanan May 6, 1873275,832 Lockwood Apr. 17, 1883 819,876 Gifiord May 8, 1906 942,955 BaneDec. 14, 1909 1,239,582 Filzer Sept. 11, 1917 2,078,207 Page et al. Apr.20, 1937 2,089,865 Voss Aug. 10, 1937 2,368,935 Lodwig Feb. 6, 1945

